The field of the invention is systems and methods for magnetic resonance imaging (“MRI”). More particularly, the invention relates to systems and methods for obtaining both perfusion and permeability measurements in a single data acquisition using a single administration of contrast agent.
Obtaining perfusion and permeability measures in brain tissue is critical for diagnosis and treatment planning. Perfusion-weighted data can be acquired with an MRI system using a T2*-weighted or T2-weighted pulse sequence during the first pass of a contrast agent. These exams typically run for 90-180 seconds depending on the protocol. From the perfusion-weighted data, perfusion measurements, such as blood volume in the tissue, blood flow in the tissue, and mean transit time can be computed.
Recent developments have indicated that it is possible to monitor the leakage of contrast from the blood plasma to a tumor or lesion. This leakage is monitored by dynamic T1-weighted imaging and requires scanning for 4-8 minutes post administration of the contrast agent. Furthermore, some pre-contrast imaging is required to provide information for the models that generate the permeability measures.
Currently, perfusion and permeability studies are conducted on different days to allow the use of full does of contrast. This is expensive because it requires two sessions. It is also inconvenient for the patient, who must make two separate trips for the different imaging scans.
As an alternative approach, perfusion and permeability studies can be conducted serially using two separate administrations of levels of contrast agent to minimize the patient's exposure to the contrast agent. These measurements are thus compromised by the non-optimal levels of contrast agent.
In light of the foregoing, it would be desirable to provide a system and method capable of obtaining both perfusion and permeability measurements in a single imaging session using an MRI system and a single, full dose of contrast agent.